1. Field of the Invention
The present invention relates to a suspension arm mounting structure in which the wheel alignment can be adjusted by displacing a bolt for fastening a suspension arm to a vehicle body in a required direction through rotation of plate cams.
2. Description of the Related Art
Conventionally known is a suspension arm mounting structure in which a plate cam composed of an eccentric disc is connected to a bolt for fastening a connecting portion of a suspension arm to a vehicle body in such a manner as to prohibit a relative rotation therebetween, whereby the bolt can be displaced in a direction orthogonal to an axis thereof when the bolt is operated to rotate for adjustment of the wheel alignment (refer to the official gazette of Japanese Patent Publication No. 2627940 or the like).
FIG. 3 shows a conventional suspension arm mounting structure as described above. In this structure, a pair of mounting bushes 2, 3 of a suspension arm 1 are adapted to be fastened to brackets 4, 5 on a vehicle body side, respectively, with a bolt 31 and a nut 32. A plate cam 33 is provided integrally with a head of the bolt 33, and a plate cam 34 having an external cam profile identical to that of the cam 33 is fitted on a shank of the bolt 31 at a position where apexes of the cam profiles of both the plate cams are aligned with each other in such a manner as to prohibit a relative rotation between the bolt 31 and the plate cam 34.
A pair of guides 6 is fixedly provided on each side of the respective brackets 4, 5 in such a manner as to face each other with an elongated hole 7 therebetween so that the pair of guides 6 regulate the outer circumference of each of the plate cams 33, 34 when they are assembled in place. The bolt 31 can be displaced in a longitudinal direction of the elongated hole 7, that is, a direction orthogonal to an axis of the bolt 31 when both the plate cams 33, 34 are rotated in an interlocking fashion by turning the head of the bolt 31 with a turning tool such as a wrench.
However, in the above construction in which the pair of plate cams 33, 34 is connected to the bolt 31 in such a manner as to prohibit a relative rotation between the plate cams and the bolt, after a wheel alignment adjustment is completed by turning the bolt 31, tightening has to be carried out on the side of the nut 32, and this requires a certain space to be secured on both sides of each bracket 4, 5 so that the turning tool can be inserted thereinto for a turning operation. In addition, when tightening the nut 32, a retaining tool has to be brought into engagement with the head of the bolt 31 while the nut 32 is turned with the turning tool so that the bolt 31 is restrained from being turned together in order to keep a once adjusted wheel alignment, thus this causing a troublesome operation.
The present invention was made to solve the problem inherent in the related art, and a main object thereof is to provide a suspension arm mounting structure constructed not only to require less work space for performing wheel alignment adjustment work but also to improve the workability.
With a view to attaining the above object, there is provided a suspension arm mounting structure including, a bolt and a nut fastening a mounting end portion of a suspension arm relative to a vehicle body, a pair of plate cams located at opposite ends of saidbolt, saidpair of plate cams being rotated so as to displace said bolt in a direction orthogonal to an axis thereof, whereby the wheel alignment is adjustable, and a cylindrical collar provided around a shank portion of said bolt. One end of said cylindrical collar provided with one of said pair of plate cams and a first engagement portion for engagement with a turning tool in such a manner as to prohibit a relative rotation therebetween. The other end of said cylindrical collar having a second engagement portion prohibiting a relative rotation between said cylindrical collar and the other of said pair of plate cams.
The one of the pair of plate cams and the engagement portion for engagement with the turning tool are formed integrally with each other relative to the cylindrical collar. In addition to this construction, the plate cam and the engagement portion may be constructed such that they are formed separately and thereafter connected to each other in such a manner as to prohibit a relative rotation therebetween. Moreover, although the other of the pair of plate cams and the nut may be constructed as separate members, they may be constructed integrally with each other in such a manner as to prohibit a relative rotation therebetween. Especially, if they are so constructed, not only can the number of components used be reduced but also the nut is restrained from rotating by restraining the cylindrical collar from rotating by the turning tool engagement portion on the side of the head of the bolt when the bolt is tightened at the head thereof. Thus, the adjustment of the wheel alignment, tightening of the bolt after such an adjustment and prevention of a deviation from an adjusted position can all be performed only on the side of the head of the bolt, and therefore there is provided an advantage that there is no need to insert any tool on the side of the nut, thereby making it possible to reduce further the work space and improve the workability.